Lighthouse3d.com >> GLUT Tutorial >> Avoiding the Idle Func >> The Code So Far VIII
以下代码用glutPostRedisplay函数代替了原来的空闲函数的回调.
#include <stdio.h>
#include <stdlib.h>
#include <math.h> #ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif // angle of rotation for the camera direction
float angle = 0.0f; // actual vector representing the camera's direction
float lx=0.0f,lz=-1.0f, ly = 0.0f; // XZ position of the camera
float x=0.0f, z=5.0f, y = 1.75f; // the key states. These variables will be zero
//when no key is being presses
float deltaAngle = 0.0f;
float deltaMove = ;
int xOrigin = -; // width and height of the window
int h,w; // variables to compute frames per second
int frame;
long time, timebase;
char s[]; // variables to hold window identifiers
int mainWindow, subWindow1,subWindow2,subWindow3;
//border between subwindows
int border = ; void setProjection(int w1, int h1)
{
float ratio;
// Prevent a divide by zero, when window is too short
// (you cant make a window of zero width).
ratio = 1.0f * w1 / h1;
// Reset the coordinate system before modifying
glMatrixMode(GL_PROJECTION);
glLoadIdentity(); // Set the viewport to be the entire window
glViewport(, , w1, h1); // Set the clipping volume
gluPerspective(,ratio,0.1,);
glMatrixMode(GL_MODELVIEW);
} void changeSize(int w1,int h1) { if(h1 == )
h1 = ; // we're keeping these values cause we'll need them latter
w = w1;
h = h1; // set subwindow 1 as the active window
glutSetWindow(subWindow1);
// resize and reposition the sub window
glutPositionWindow(border,border);
glutReshapeWindow(w-*border, h/ - border*/);
setProjection(w-*border, h/ - border*/); // set subwindow 2 as the active window
glutSetWindow(subWindow2);
// resize and reposition the sub window
glutPositionWindow(border,(h+border)/);
glutReshapeWindow(w/-border*/, h/ - border*/);
setProjection(w/-border*/,h/ - border*/); // set subwindow 3 as the active window
glutSetWindow(subWindow3);
// resize and reposition the sub window
glutPositionWindow((w+border)/,(h+border)/);
glutReshapeWindow(w/-border*/,h/ - border*/);
setProjection(w/-border*/,h/ - border*/);
} void drawSnowMan() { glColor3f(1.0f, 1.0f, 1.0f); // Draw Body
glTranslatef(0.0f ,0.75f, 0.0f);
glutSolidSphere(0.75f,,); // Draw Head
glTranslatef(0.0f, 1.0f, 0.0f);
glutSolidSphere(0.25f,,); // Draw Eyes
glPushMatrix();
glColor3f(0.0f,0.0f,0.0f);
glTranslatef(0.05f, 0.10f, 0.18f);
glutSolidSphere(0.05f,,);
glTranslatef(-0.1f, 0.0f, 0.0f);
glutSolidSphere(0.05f,,);
glPopMatrix(); // Draw Nose
glColor3f(1.0f, 0.5f, 0.5f);
glRotatef(0.0f,1.0f, 0.0f, 0.0f);
glutSolidCone(0.08f,0.5f,,); glColor3f(1.0f, 1.0f, 1.0f); } void renderBitmapString(
float x,
float y,
float z,
void *font,
char *string) { char *c;
glRasterPos3f(x, y,z);
for (c=string; *c != '\0'; c++) {
glutBitmapCharacter(font, *c);
}
} void restorePerspectiveProjection() { glMatrixMode(GL_PROJECTION);
// restore previous projection matrix
glPopMatrix(); // get back to modelview mode
glMatrixMode(GL_MODELVIEW);
} void setOrthographicProjection() { // switch to projection mode
glMatrixMode(GL_PROJECTION); // save previous matrix which contains the
//settings for the perspective projection
glPushMatrix(); // reset matrix
glLoadIdentity(); // set a 2D orthographic projection
gluOrtho2D(, w, h, ); // switch back to modelview mode
glMatrixMode(GL_MODELVIEW);
} void computePos(float deltaMove) { x += deltaMove * lx * 0.1f;
z += deltaMove * lz * 0.1f;
} // Common Render Items for all subwindows
void renderScene2() { // Draw ground glColor3f(0.9f, 0.9f, 0.9f);
glBegin(GL_QUADS);
glVertex3f(-100.0f, 0.0f, -100.0f);
glVertex3f(-100.0f, 0.0f, 100.0f);
glVertex3f( 100.0f, 0.0f, 100.0f);
glVertex3f( 100.0f, 0.0f, -100.0f);
glEnd(); // Draw 36 SnowMen
for(int i = -; i < ; i++)
for(int j=-; j < ; j++)
{
glPushMatrix();
glTranslatef(i*10.0f, 0.0f, j * 10.0f);
drawSnowMan();
glPopMatrix();
}
} // Display func for main window
void renderScene() {
glutSetWindow(mainWindow);
glClear(GL_COLOR_BUFFER_BIT);
glutSwapBuffers();
} // Display func for sub window 1
void renderScenesw1() { glutSetWindow(subWindow1); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity();
gluLookAt(x, y, z,
x + lx,y + ly,z + lz,
0.0f,1.0f,0.0f); renderScene2(); // display fps in the top window
frame++; time=glutGet(GLUT_ELAPSED_TIME);
if (time - timebase > ) {
sprintf(s,"Lighthouse3D - FPS:%4.2f",
frame*1000.0/(time-timebase));
timebase = time;
frame = ;
} setOrthographicProjection(); glPushMatrix();
glLoadIdentity();
renderBitmapString(,,,GLUT_BITMAP_HELVETICA_12,s);
glPopMatrix(); restorePerspectiveProjection(); glutSwapBuffers();
} // Display func for sub window 2
void renderScenesw2() { glutSetWindow(subWindow2); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity();
gluLookAt(x, y+, z,
x ,y - ,z,
lx,,lz); // Draw red cone at the location of the main camera
glPushMatrix();
glColor3f(1.0,0.0,0.0);
glTranslatef(x,y,z);
glRotatef(-(angle+deltaAngle)*180.0/3.14,0.0,1.0,0.0);
glutSolidCone(0.2,0.8f,,);
glPopMatrix(); renderScene2(); glutSwapBuffers();
} // Display func for sub window 3
void renderScenesw3() { glutSetWindow(subWindow3); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity();
gluLookAt(x-lz* , y, z+lx*,
x ,y ,z ,
0.0f,1.0f,0.0f); // Draw red cone at the location of the main camera
glPushMatrix();
glColor3f(1.0,0.0,0.0);
glTranslatef(x,y,z);
glRotatef(-(angle+deltaAngle)*180.0/3.14,0.0,1.0,0.0);
glutSolidCone(0.2,0.8f,,);
glPopMatrix(); renderScene2(); glutSwapBuffers();
} // Global render func
void renderSceneAll() { // check for keyboard movement
if (deltaMove) {
computePos(deltaMove);
glutSetWindow(mainWindow);
glutPostRedisplay();
} renderScene();
renderScenesw1();
renderScenesw2();
renderScenesw3();
} // -----------------------------------
// KEYBOARD
// ----------------------------------- void processNormalKeys(unsigned char key, int xx, int yy) { if (key == ) {
glutDestroyWindow(mainWindow);
exit();
}
} void pressKey(int key, int xx, int yy) { switch (key) {
case GLUT_KEY_UP : deltaMove = 0.5f; break;
case GLUT_KEY_DOWN : deltaMove = -0.5f; break;
}
glutSetWindow(mainWindow);
glutPostRedisplay(); } void releaseKey(int key, int x, int y) { switch (key) {
case GLUT_KEY_UP :
case GLUT_KEY_DOWN : deltaMove = ;break;
}
} // -----------------------------------
// MOUSE
// ----------------------------------- void mouseMove(int x, int y) { // this will only be true when the left button is down
if (xOrigin >= ) { // update deltaAngle
deltaAngle = (x - xOrigin) * 0.001f; // update camera's direction
lx = sin(angle + deltaAngle);
lz = -cos(angle + deltaAngle); glutSetWindow(mainWindow);
glutPostRedisplay();
}
} void mouseButton(int button, int state, int x, int y) { // only start motion if the left button is pressed
if (button == GLUT_LEFT_BUTTON) { // when the button is released
if (state == GLUT_UP) {
angle += deltaAngle;
deltaAngle = 0.0f;
xOrigin = -;
}
else {// state = GLUT_DOWN
xOrigin = x; }
}
} // -----------------------------------
// MAIN and INIT
// ----------------------------------- void init() { glClearColor(0.0, 0.0, 0.0, 0.0);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE); // register callbacks
glutIgnoreKeyRepeat();
glutKeyboardFunc(processNormalKeys);
glutSpecialFunc(pressKey);
glutSpecialUpFunc(releaseKey);
glutMouseFunc(mouseButton);
glutMotionFunc(mouseMove);
} int main(int argc, char **argv) { // init GLUT and create main window
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowPosition(,);
glutInitWindowSize(,);
mainWindow = glutCreateWindow("Lighthouse3D - GLUT Tutorial"); // callbacks for main window
glutDisplayFunc(renderSceneAll);
glutReshapeFunc(changeSize); // Removing the idle function to save CPU and GPU
//glutIdleFunc(renderSceneAll);
init(); // sub windows
subWindow1 = glutCreateSubWindow(mainWindow, border,border,w-*border, h/ - border*/);
glutDisplayFunc(renderScenesw1);
init(); subWindow2 = glutCreateSubWindow(mainWindow, border,(h+border)/,w/-border*/, h/ - border*/);
glutDisplayFunc(renderScenesw2);
init(); subWindow3 = glutCreateSubWindow(mainWindow, (w+border)/,(h+border)/,w/-border*/,h/ - border*/);
glutDisplayFunc(renderScenesw3);
init(); // enter GLUT event processing cycle
glutMainLoop(); return ;
}